I just came across this amazing research and testing site that shows what happens when a car is in a 50km/h collision. They’ve got slow mo’ video of harnesses and crates, and of course the hapless crash test doggies (not real dogs, obviously). Please don’t watch if you are prone to anxiety. 🙂
At the moment, very few products will save your large dog, or the people in the dog’s path, in a crash. Even the smaller dogs get damaged not only by being airborne, but by their harnesses snapping or constricting their bodies during the impact. A flying dog is every bit as dangerous as any other cargo.
The testers found that most products that claim some form of testing do not hold up in actual crash testing (nor are there requirements for them to). Crates made of wire buckle and open to throw the dog out, and plastic crates shatter as the dog’s body hurtles through the side. Their only value is that they’ll absolutely stop your dog causing an accident by jumping on you while you are driving.
The products that worked are listed on the site. In all cases, the most important factor seems to be really heavy duty restraints that don’t have slack in them. The harness does not allow the dog to look out the window, and the crate is right up against the back of the cargo bay.